WO2008098416A1

WO2008098416A1 - A multi-user interference cancellation rake receiver device and method

Info

Publication number: WO2008098416A1
Application number: PCT/CN2007/000532
Authority: WO
Inventors: Yantao Gu; Yuefeng Chen
Original assignee: Zte Corporation
Priority date: 2007-02-14
Filing date: 2007-02-14
Publication date: 2008-08-21
Also published as: CN101502006B; CN101502006A

Abstract

A multi-user interference cancellation RAKE receiver device in a broadband CDMA system additionally includes an interference reconstruction unit (210) and an interference elimination unit (211) on the basis of traditional RAKE receivers. The interference reconstruction unit (210) carries out interference reconstruction for the user data which has a spread spectrum factor less than or equal to the first threshold and then obtains interference data equal to the sampling rate of initial antennae data. The interference elimination unit (211) compares the delay controlled initial antennae data (208) received by antennae data delay control unit (202) with the interference data, makes a subtraction, obtains interference canceled antennae data (207) and sends it to the antennae data delay control unit (202). The data is delay controlled and used to demodulate other non-highspeed uplink data service users.

Description

RAKE receiver device with multi-user interference cancellation and working method thereof

Technical field

The present invention relates to a baseband processor uplink receiving technology of a Wideband Code Division Multiple Access (WCDMA) base station, and particularly relates to a RAKE receiver hardware implementation device and a working method for a base station uplink receiving and supporting a high speed data service. method.

Background technique

In the WCDMA wireless communication system, since the space wireless transmission environment is complicated and severe, the RAKE. receiver device is usually received. As shown in FIG. 1, the structure of a RAKE receiver apparatus of a conventional base station baseband processor is shown, including: an antenna data delay control unit, a RAKE demodulation unit, a control channel symbol processing unit, and a data channel symbol maximum ratio combining unit.

When the RAKE receiver is working, the input antenna data is directly input to the antenna data delay control unit; the antenna data delay control unit sends the antenna data to the RAKE demodulation unit by controlling the antenna data delay.

The RAKE demodulation unit performs descrambling and despreading on the delayed-processed antenna data sent by the antenna data delay control unit, and respectively performs a dedicated physical control channel (DPCCH, Dedicated Physical Control Channel) and a dedicated physics in the RAKE demodulation unit. The data channel (DPDCH, Dedicated Physical Data Channel) performs multipath demodulation. The dedicated physical control channel obtains the control channel symbol data of the user after multipath demodulation, and outputs the signal to the control channel symbol processing unit; the dedicated physical data channel obtains the data channel symbol data of the user after multipath demodulation, and outputs the data to the data. The channel symbol is greater than the merging unit.

The control channel symbol processing unit performs channel estimation and TFC transport format combination indicator (Transport Format Combination Indicator) decoding processing to generate channel estimation values for each multipath, and performs TFCI decoding to obtain each user. The actual spreading factor (SF, Spreading Factor) outputs the channel estimation and the TFCI decoding result to the data channel symbol maximum ratio combining unit.

Data channel symbol maximum ratio combining unit, according to the channel sent by the control channel symbol processing unit The estimated value and the actual spreading factor SF are subjected to channel compensation and maximum ratio combining and accumulation of the data channel symbols of each user sent after the demodulation of the RAKE demodulation unit is completed, to obtain data symbols of the final data channel.

For WCDMA systems, it is a system with limited interference.

For a general uplink voice service, since the spreading factor is relatively large (generally SF>=64), satisfactory performance can be obtained by using a conventional RAKE receiver, and the corresponding mobile station does not need to have a high transmission power. Therefore, the base station can Support more users.

However, for the uplink data service, especially the HSUPA (High Speed Uplink Packet Access) proposed by the R6 protocol, the spreading factor is small (SF<=4), and the mobile phone needs a higher transmitting power. Ensure that the base station can receive the information of the mobile phone using the traditional RAKE receiver. When the traditional RAKE receiver of the base station receives the HSUPA user service, the mobile phone signal uses a higher transmit power, while the other non-HSUPA user service signals (such as the uplink voice service) have a relatively small power, and other users demodulate the HSUPA user service. The interference at the time is relatively negligible.

However, at this time, the HSUPA signal of the mobile phone occupies a larger part of the antenna signal received by the entire base station, and when the conventional RAKE receiver demodulates the services of other non-HSUPA users, it causes a large interference, resulting in other The user's signal is disturbed and overwhelmed. In this way, other users must also increase the transmit power to allow the base station to receive the information of these users. The final result is that the total power continues to rise beyond the system tolerance and thus limit the number of users, resulting in system support. The number of users has dropped. In summary, for a base station device of a conventional RAKE receiver device, when a user of a high-speed uplink data service occurs, the normal use of other users is seriously affected, resulting in a decrease in the number of users accessing, or even inaccessibility. Therefore, there is a need for a device that can reduce the interference of high speed data service users to other users, avoiding or mitigating power ups due to interference and a drop in the number of users. SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a multi-user interference cancellation RAKE receiver device and a working method thereof for a WCDMA system, which are used to cancel the interference of high-speed uplink data service users to other non-high-speed uplink data service users, and ensure There are WCDMA high-speed uplink data The number of users in the service case overcomes the shortcoming that the number of users is drastically reduced when the conventional RAKE receiver interferes with other users in the high-speed uplink data service.

The present invention provides a multi-user interference cancellation RAKE receiver apparatus for a wideband code division multiple access system, including a RAKE demodulation unit, and an antenna data delay control unit, a control channel symbol processing unit, and a data channel symbol, respectively The maximum is connected to the merging unit, and the control channel symbol processing unit is further connected to the data channel symbol maximum ratio merging unit, characterized in that the device further comprises an interference reconstruction unit and an interference cancellation unit, wherein:

The interference reconstruction unit is respectively connected to the data channel symbol maximum ratio combining unit and the control channel symbol processing unit, and receives the data channel data symbol of the high speed uplink data service user from the data channel symbol maximum ratio combining unit, according to the data symbol symbol extension The frequency factor determines whether the user needs to perform interference reconstruction. When the spreading factor is less than or equal to the first threshold, the data channel data symbol of the user is received according to the user scrambling code and channelization code information received from the control channel symbol processing unit. Perform interference reconstruction, and obtain interference data outputting the same as the antenna data sampling rate to the interference cancellation unit, otherwise directly output the data channel data symbol of the user for symbol level processing;

The interference cancellation unit receives the initial antenna data from the antenna from the antenna data delay control unit, and performs subtraction from the interference data outputted from the interference reconstruction unit, and obtains the antenna data with the interference removed, and sends the antenna data to the antenna data delay control unit. , RAKE demodulation for other users.

Further, in the RAKE receiver device of the present invention:

The antenna data delay control unit is configured to perform delay control on the initial antenna data received from the antenna together with the antenna data after the multi-user interference cancellation received from the interference cancellation unit, and send the initial antenna to the RAKE solution. The modulation unit is used for data demodulation of the high-speed uplink data service user, and the antenna data after the interference cancellation is sent to the RAKE demodulation unit for data demodulation of other non-high-speed uplink data service users;

The RAKE demodulation unit performs multipath demodulation on the antenna data sent by the antenna data delay control unit to obtain data symbols of different users, and respectively sends the data symbols according to the control channel data symbols and the selected channel data symbols of the user to the control channel. a symbol processing unit and a data channel symbol maximum ratio combining unit;

The control channel symbol processing unit is configured to receive each received from the RAKE demodulation unit The control channel data symbols of the user are processed, the channel estimation values of each multipath are generated, and the transmission format combination indicator is decoded to obtain the actual spreading factor of each user, and the channel estimation value and the spreading factor are sent to the data channel. The symbol maximum ratio combining unit sends the scrambling code and channelization code information of each high-speed uplink data service user to the interference repeating unit;

The data channel symbol maximum ratio combining unit performs data channel data symbols of each user sent after the RAKE demodulation unit demodulates according to the channel estimation value sent by the control channel symbol processing unit and the actual spreading factor. The channel compensation and the maximum ratio are combined to obtain the data symbols of the final data channel, and the data channel data symbols of each high-speed uplink data service user are sent to the interference reconstruction unit.

Further, the interference reconstruction unit includes: a comparator, an accumulator, a pulse shaping filter, an interpolation filter, and a first one corresponding to each user between the comparator and the accumulator A multiplier, a second multiplier, a scrambling code, and a channelization code are used to generate a modulo, where:

a comparator, configured to receive data symbols of a data channel of each user of the high-speed uplink data service, and determine whether the user needs to perform interference reconstruction according to an actual spreading factor of each user, when the spreading factor is less than or equal to the first At the threshold, the first multiplier corresponding to the user is sent, otherwise, the data symbols of the data channel of the user are directly output for symbol level processing;

a first multiplier that multiplies a data symbol of a data channel received from the comparator with a channel estimation parameter of the user to obtain a data symbol with channel information and sends it to a second multiplier; 'scrambling code and channelization code generation And generating, by the module according to the actual spreading factor, the scrambling code and the channelization code parameter of the user received from the control channel symbol processing unit, the scrambling code and the channelization code of the user are sent to the second multiplier;

a second multiplier, performing amplification and scrambling on the data symbol with channel information received from the first multiplier according to the scrambling code and channelization code of the user received from the scrambling code and the channelization code generating module a multiplication operation, outputting chip data of the user with channel information to the accumulator;

An accumulator for accumulating chip data with channel information received by a second multiplier corresponding to each user of the high speed uplink data service, and obtaining chip data of the reconstructed channel information of all users is output to the pulse forming Filter; pulse shaping filter, reconstructed channel for all high-speed uplink data service users received The chip data of the information is subjected to pulse shaping processing and sent to the interpolation filter;

The interpolation filter interpolates the reconstructed chip data with channel information of all users after the pulse shaping, and obtains interference data with the same sampling rate as the actual initial antenna data of the user, and outputs the interference data to the interference cancellation unit. .

Further, the interference reconstruction unit receives the data symbol of the data channel of the high-speed uplink data service user from the data channel symbol maximum ratio combining unit, and determines whether the user needs to perform interference reconstruction according to the spreading factor therein If the spreading factor is greater than the first threshold, the data symbols of the user's data channel are directly output for symbol level processing. Further, the first threshold of the frequency factor is equal to four.

Further, the interference cancellation unit includes a delayer and a subtractor, where:

a delay device for delaying initial antenna data input from the antenna end, aligning the initial antenna data with interference data received from the interference reconstruction unit; and a subtractor for delay-aligning the common input The initial antenna data is subtracted from the interference data output by the interference reconstruction unit, and the antenna data with the high-speed uplink data service signal interference is output, and sent to the antenna data delay control unit for data demodulation of other non-high-speed uplink data service users. .

The present invention also provides a method for operating a RAKE receiver device based on the multi-user interference cancellation described above, comprising the steps of:

(1) The initial antenna data from the antenna is delayed by the antenna data delay control unit, and then sent to the RAKE demodulation unit, the control channel symbol processing unit, the data channel symbol maximum ratio combining unit processing, and the control channel symbol processing. The unit obtains the channel estimation value of each multipath, the actual spreading factor, the scrambling code of each user, and the channelization code information, and obtains the data symbol of the data channel of the user of the high speed uplink data service in the data channel symbol maximum ratio combining unit. Into the interference reconstruction unit;

(2) The interference reconstruction unit performs interference reconstruction on the data symbols of the high-speed uplink data service user data channel whose input spreading factor is less than or equal to the first threshold, and obtains interference data with the same initial data sampling rate to the interference. Elimination unit;

(3) The initial antenna data received by the interference cancellation unit after delay control is aligned with the interference data outputted from the interference reconstruction unit, and subtracted, and the antenna data with the interference removed is sent to the antenna. The data delay control unit is used for RAKE demodulation of other users after delay control.

Further, the step (1) further includes:

(1 - 1) delaying control of the initial antenna data received from the antenna by the antenna data delay control unit, and transmitting to the RAKE demodulation unit;

(1 - 2) The RAKE demodulation unit performs multipath demodulation on the initial antenna data sent by the antenna data delay control unit to obtain data symbols of different users, which are respectively sent according to the control channel data symbols of the user and the data channel data symbols. Giving a control channel symbol processing unit and a data channel symbol maximum ratio combining unit;

(1-3) processing, by the control channel symbol processing unit, the control channel data symbols of each user received from the RAKE demodulation unit, generating channel estimation values for each multipath, and performing transmission format combination indicator decoding The actual spreading factor of each user sends the channel estimation value and the spreading factor to the data channel symbol maximum ratio combining unit, and sends the scrambling code and channelization code information of each high-speed uplink data service user to the interference reconstruction unit;

(1 - 4) a data channel of each user sent by the RAKE demodulation unit after demodulation by the data channel symbol maximum ratio combining unit according to the channel estimation value sent by the control channel symbol processing unit and the actual spreading factor The data symbols are subjected to channel compensation and maximum ratio combining, and the data symbols of the data channel of the high-speed uplink data service user are sent to the interference reconstruction unit.

Further, the step (2) further includes:

Receiving, by the comparator, the data symbols of the data channel of each user, comparing the actual spreading factor and the first threshold, and directly outputting the data symbols of the data channel of the user when the spreading factor is greater than the first threshold, otherwise And multiplying the data symbol of the retransmitted data channel with the channel estimation parameter of the user by using a first multiplier corresponding to the user, to obtain a data symbol with channel information, where the value of the first threshold is 4;

Generating a scrambling code and a channelization code of the user by a scrambling code and a channelization code generating module according to an actual spreading factor, a scrambling code, and a channelization code parameter of the user received from the control channel symbol processing unit;

And expanding, by the second multiplier, the data symbols with channel information received from the first multiplier according to the scrambling code and the channelization code of the user received from the scrambling code and the channelization code generating module. a multiplication operation of the disturbance, outputting the chip data of the user with channel information to the accumulator; using the accumulator to accumulate the chip data with the channel information received from the second multiplier corresponding to each user, to obtain all users The reconstructed chip data with channel information is output to a pulse shaping filter;

Using the pulse shaping filter, the reconstructed chip data of the channel information of all the users received is subjected to pulse shaping processing and sent to the interpolation filter;

The interpolated filter is used to interpolate the reconstructed chip data with channel information of all users after the pulse shaping process, and obtain interference data of the same sampling rate as the actual antenna data of the user, and output the interference data to the interference cancellation unit.

Further, the step (3) is further divided into:

Delaying the initial antenna data input from the antenna end by using a delay device, and aligning the input antenna data with the interference data received from the interference reconstruction unit;

The subtractor is used to subtract the antenna data of the common input delay alignment and the antenna interference data output by the interference reconstruction unit, and output the antenna data of the high-speed uplink data service signal interference, and send it to the antenna data delay control unit. After delay control, it is used for RAKE demodulation of other non-high speed uplink data service users.

The multi-user interference cancellation RAKE receiver device of the present invention adds the function of interference reconstruction and interference cancellation when the high-speed uplink data service is interfered with other users on the basis of the conventional RAKE receiver device, and the interference is cancelled. The subsequent antenna data is used for RAKE demodulation by other non-HSUPA users. Therefore, the conventional RAKE receiver has the disadvantages that other users cannot access or have poor access performance when high-speed uplink data services exist. Moreover, when the present invention is implemented, only a small number of high-speed uplink data service users' interference reconstruction and interference cancellation functions are added, and the control implementation is relatively simple, easy to implement, and uses less hardware resources.

In short, compared with the traditional RAKE receiver, although some hardware resources are added, the uplink receiving performance of the base station is improved, the interference between the high-speed uplink data service user and other users is minimized, and the interference due to the increase of interference is avoided. The number of incoming users is reduced or even unable to access. BRIEF abstract

1 is a schematic structural diagram of a conventional RAKE receiver apparatus in a WCDMA system; FIG. 2 is a schematic diagram of a multiuser interference cancellation RAKE receiver apparatus according to an embodiment of the present invention; and FIG. 3 is a multiuser interference cancellation RAKE receiver according to an embodiment of the present invention; Interference reconstruction unit structure diagram in the device;

Fig. 4 is a structural diagram of an interference canceling unit in a multiuser interference canceling RAKE receiver apparatus in the embodiment of the present invention.

Preferred embodiment of the invention

The technical solutions of the present invention are further described in detail below with reference to the accompanying drawings and specific embodiments. In order to overcome the shortcomings of the conventional RAKE receiver causing interference to other users (non-high-speed uplink data service users) when accessing high-speed uplink data services, the number of users is drastically reduced, and the number of users in the case of WCDMA high-speed uplink data services is guaranteed. This embodiment provides a RAKE receiver apparatus based on WCDMA multi-user interference cancellation.

For a RAKE receiver in a WCDMA system, access to the user may include the following three cases:

(1) All are non-HSUPA users accessing. At this time, since the interference is 0, it is equivalent to the antenna data delay, and the access process corresponds to the traditional RAKE access process;

(2) The situation of both HSUPA users and non-HSUPA users;

Since HSUPA is an E-DCH channel, it is different from the physical channel of a non-HSUPA user.

In the RAKE processing, it is judged that SF<=4 is only for the HSUPA user, and the initially input antenna data is used for access, and the non-HSUPA user uses the antenna data after the interference cancellation. The so-called interference cancellation refers to the antenna data that is initially input. The interference reconstruction is performed as the interference HSUPA data, and the reconstructed interference data is subtracted.

(3) All cases of HSUPA users;

RAKE processing can be performed using directly input antenna data. As shown in FIG. 2, a schematic structural diagram of a RAKE receiver apparatus for multi-user interference cancellation of the WCDMA system provided by this embodiment is shown. The device comprises: an antenna data delay control unit, a RAKE demodulation unit, a control channel symbol processing unit, a data channel symbol maximum ratio combining unit, an interference reconstruction unit, and an interference cancellation unit. Compared with the conventional RAKE receiver apparatus shown in FIG. 1, the RAKE receiver apparatus of the multi-user interference cancellation shown in FIG. 2 newly adds an interference reconstruction unit and an interference cancellation unit based on the conventional RAKE receiver apparatus.

The RAKE receiving apparatus shown in FIG. 2, when there is a high-speed uplink data service (HSUPA) user access, the antenna data initially received from the antenna end includes the HUSPA user service and other non-HUSPA user services (for example, voice service user service). The antenna data is connected to an antenna data delay control unit. The RAKE receiving device buffers the antenna data. When the base station selects to access the high-speed uplink data service user, the base station does not interfere with the access of other non-HSUPA service users because of its high access power. The descrambling and despreading can be directly performed, and corresponding specific physical control channel symbols and specific physical data channel symbols are output. On the other hand, when the base station selects other non-HSUPA service users to access, the high-speed uplink data service will seriously interfere with the access of other HSUPA service users, and affect the number of access and access users of other users.

In the RAKE device in this embodiment, the interference reconstruction unit performs interference reconstruction on the data channel symbols of the high-speed uplink data service in the antenna data, and sends interference into the RAKE device in this embodiment. The cancellation unit, the interference-cancelled antenna data output by the last interference cancellation unit is returned to the antenna data delay control unit as a new antenna data stream for RAKE demodulation of other users. among them:

1) The interference reconstruction unit first determines whether to participate in interference reconstruction according to the actual SF of the HSUPA user. If SF<=4, the data symbol of the user's data channel is subjected to interference reconstruction, otherwise interference reconstruction is not performed. The interference reconstruction is to multiply the data symbol of the HSUPA user data channel by the channel estimation value parameter of the user, and then perform scrambling and spreading according to the actual SF of the user, the scrambling code number of the user, and the spreading code number. Finally, the data of the plurality of users scrambled and expanded is accumulated as the total interference, and then pulse shaping and interpolation are performed, and the same interference data as the antenna data sampling rate is obtained and sent to the interference cancellation unit.

2) The interference cancellation unit delays the antenna data originally input (including the HSUUPA user and the non-HSUPA user data), and then performs interference with the interference data output by the interference reconstruction unit. Subtract, the result is to remove the interference antenna data (ie, non-HSUPA user data), and then send the output back to the antenna data delay control unit as an antenna data stream, and send it to the RAKE demodulation unit as a delay after the delay. Antenna data for RAKE demodulation of non-high speed uplink data service users.

In the multi-user interference cancellation RAKE receiver apparatus shown in Fig. 2, the functions of the existing modules are as follows:

The antenna data delay control unit is configured to perform buffer delay processing on the initially input antenna data, and control the antenna data after multi-user interference cancellation together, and jointly perform antenna data stream numbering for subsequent RAKE demodulation a unit, sending antenna data after multi-user interference cancellation to a subsequent RAKE demodulation unit to descramble and despread antenna data of other non-high-speed uplink data service users;

The RAKE demodulation unit performs multipath demodulation on the antenna data sent by the antenna data delay control unit to obtain symbol data of different users, and sends the symbol data to the control channel symbol processing unit and the data channel symbol according to the control channel and the data channel of the user respectively. Maximum ratio combining unit;

The control channel symbol processing unit processes the control channel symbols of each user sent after the demodulation of the RAKE demodulation unit is completed, generates channel estimation values for each multipath, and performs TFCI decoding to obtain actuality of each user. SF, sending the information to the data channel symbol maximum ratio combining unit for maximum ratio combining, and sending the scrambling code and channelization code information of the HSUPA user to the interference reconstruction unit;

The data channel symbol maximum ratio combining unit, according to the channel estimation value sent by the control channel symbol processing unit and the actual SF, performs channel compensation and maximum for each user's data channel symbol sent after the RAKE demodulation unit demodulates the completion. The data symbols of the final data channel are obtained by accumulating more than the combination. The data symbol of the final data channel of the HSUPA user is sent to the interference reconstruction unit.

FIG. 3 is a structural diagram of an interference reconstruction unit in a multiuser interference cancellation RAKE receiver apparatus according to this embodiment. As shown in FIG. 3, the interference reconstruction unit mainly includes: a comparator, a multiplier, an n-set scrambling code and a channelization code generating module, an accumulator, a pulse shaping filter, and an interpolation filter.

• In Figure ³ , each high-speed uplink data service from the data channel symbol maximum ratio merging unit The data symbol of the final data channel of the user passes through a comparator that is judged according to the SF of the user. When SF<=4, the data symbol of the final data channel of the user enters the next level processing through the comparator, otherwise, When SF>4, the interference to other users is small, and it can be directly output for symbol level processing.

The data symbols of the comparator are first multiplied with the channel estimation parameters of the high-speed uplink data service user to obtain data symbols with channel information; then the data symbols are subjected to multiplication operations of the scramble and scramble to obtain the channel information of the user. Chip data. The channelization code and the scrambling code required for the scrambling are derived from the scrambling code and the channelization code generating module, and the module generates the channelization code and the scrambling code according to the user parameters of the scrambling code number and the channelization code number of the user. of.

The multi-user in the interference reconstruction unit means that the antenna data initially received includes multiple

In the case of HSUPA. users, the interference data of each HSUPA user is reconstructed to obtain the total interference data of all HSUPA users.

The data symbol of the data channel of the user 1 is first multiplied with the channel parameter of the user 1, and the scrambling code and channelization code generating module 1 generates a scrambling code and a channelization code according to the parameters of the user 1, and the second multiplier corresponding to the user 1 Performing a multiplication operation of the scramble and scramble to obtain the chip data of the user 1 with channel information;

The data symbol of the data channel of the user 2 is first multiplied with the channel parameter of the user 2, and the scrambling code and channelization code generating module 2 generates a scrambling code and a channelization code according to the parameters of the user 2, and the second multiplier corresponding to the user 2 The multiplication operation of the scrambling is performed to obtain the chip data of the user 2 with channel information.

The data symbol of the data channel of the user n is first multiplied with the channel parameter of the user _n , and the scrambling code and channelization code generating module n generates a scrambling code and a channelization code according to the parameter of the user n, and the second multiplier corresponding to the user n The multiplication operation of the scramble and the scramble is performed to obtain the chip data of the user n with the channel information.

All the antenna data reconstructed by the HSUPA user are accumulated in the accumulator to obtain the reconstructed chip data with channel information of all users, but at this time, the chip data is 1 chip rate, and the actual antenna data is sampled. The rate is different, and the actual antenna data is also pulse shaped. Waves. In order to obtain the truly reconstructed antenna data, the chip data obtained by the HSUPA multi-user accumulation also needs to pass through the pulse shaping filter and then the interpolation filter, so that the same sampling rate as the actual antenna data can be obtained. In this way, the reconstruction of the interference data is completed, and the reconstructed interference data output is sent to the interference cancellation unit to perform interference cancellation.

Fig. 4 is a structural diagram of an interference canceling unit in a multiuser interference canceling RAKE receiver apparatus according to the present embodiment. The interference cancellation unit is mainly composed of a delayer and a subtractor, wherein:

a delay device for delaying the antenna data initially input by the antenna end to align with the antenna interference signal output by the interference reconstruction unit;

The initial antenna data after the delay and the antenna interference signal output by the interference reconstruction unit are input to the subtractor for subtraction, and the output is the antenna data after the high-speed uplink data service signal is removed, that is, in the antenna data for eliminating interference, The high-speed uplink data service signal is no longer included, but only the non-high-speed uplink data service signal is included, and the interference-canceled antenna data is returned to the antenna data delay control unit, and sent to the RAKE demodulation unit for RAKE of other non-HSUPA service users. Demodulation, thereby achieving the purpose of reducing interference.

The RAKE receiver device based on the multi-user interference cancellation shown in FIG. 2 performs a multi-user interference cancellation process, which includes the following steps:

Step 1: The antenna data initially input from the antenna is sent to the antenna data delay control unit, and the antenna data delay control unit delays the initial input antenna data to judge the HSUPA and the non-HSUPA, and the initial for the HSUPA The accessed antenna data is sent to the RAKE demodulation unit for demodulation, and the antenna data after the interference cancellation is sent to the RAKE demodulation unit for demodulation for the non-HSUPA. The second step: the RAKE demodulation unit performs descrambling and despreading the input antenna data streams, and sends the demodulated user control channel symbol data and the data channel symbol data to the control channel symbol processing unit and the data respectively. Channel symbol maximum ratio combining unit;

Step 3: The control channel symbol processing unit processes the control channel symbols, generates channel estimation values for each multipath, and performs TFCI decoding to obtain the actual SF of each user, and estimates the channel. And the actual SF information is sent to the data channel symbol maximum ratio combining unit, and the information of the channel estimation, the actual SF, the scrambling code number, and the spreading code number of each HSUPA user is sent to the interference reconstruction unit as a channel parameter;

The fourth step: the data channel symbol maximum ratio combining unit performs the data channel symbol of each HSUPA user sent after the demodulation of the RAKE demodulation unit is completed according to the channel estimation value sent by the control channel symbol processing unit and the actual SF. The channel compensation and the maximum ratio combining are accumulated, and the data symbols of the final data channel are obtained and sent to the interference reconstruction unit;

The fifth step: the interference reconstruction unit first determines whether it is necessary to perform interference reconstruction on the received data symbols, and selects the data symbol of the user's data channel of SF<=4 multiplied by the channel estimation parameter of the user, and then according to the user's The actual SF, the user's scrambling code number and the spreading code number are scrambled and expanded, multi-user accumulation is performed, and then the data stream with the same sampling rate of the antenna data is sent to the interference through the pulse shaping filter and the interpolation filter. The unit is eliminated; if SF>4, the data symbols of the HSUPA user can be directly output for symbol level processing.

Step 6: The interference cancellation unit delays the input antenna data first, aligns with the interference signal output by the interference reconstruction unit, and then subtracts the input interference data from the input antenna data to obtain the interference-removed antenna data, and then sends the antenna data. The antenna data delay control unit is used for RAKE demodulation by other users.

High-speed uplink data service, when the spreading factor SF = 2 or 4, especially SF = 2, the inter-symbol interference is very large due to the channelization code tree between other user channels, and the inter-symbol interference is too large, however, By using the apparatus and method of the present invention, interference reconstruction and interference cancellation are performed on data of a user SF<=4 of a high-speed uplink data service, and RAKE demodulation for other users after re-inputting can effectively reduce other non-high speeds. Inter-symbol interference between users of upstream data services.

In summary, by increasing interference cancellation and interference reconstruction, the high-speed uplink data service is cancelled as interference of other users, so that the antenna data after interference cancellation is used for RAKE demodulation of other users, thereby improving the traditional RAKE. When the high-speed uplink data service exists in the receiver, other users cannot access or have poor access performance. The invention improves the uplink receiving performance of the base station, and ensures that the system can still support the capability of more users in the case of high-speed uplink data services. Industrial applicability

The multi-user interference cancellation RAKE receiver device disclosed in the present invention can effectively offset the impact on other users when accessing users of high-speed uplink data services in the WCDMA system, and avoid or reduce the power increase and the decrease in the number of users due to interference.

Claims

Claim

A multi-user interference cancellation RAKE receiver apparatus for a wideband code division multiple access system, comprising a RAKE demodulation unit, the antenna data delay control unit, the control channel symbol processing unit, and the data channel symbol maximum The control channel symbol processing unit is further connected to the data channel symbol maximum ratio combining unit, and the apparatus further includes an interference reconstruction unit and an interference cancellation unit, where:

2. The multi-user interference cancellation RAKE receiver apparatus of claim 1 wherein:

The RAKE demodulation unit performs multipath demodulation on the antenna data sent by the antenna data delay control unit to obtain data symbols of different users, and respectively sends the control channel symbol according to the control channel data symbol and the data channel data symbol of the user. Processing unit and data channel symbol maximum ratio combining unit;

The control channel symbol processing unit is configured to receive each received from the RAKE demodulation unit The control channel data symbols of the user are processed, the channel estimation values of each multipath are generated, and the transmission format combination indicator is decoded to obtain the actual spreading factor of each user, and the channel estimation value and the spreading factor are sent to the data channel. The symbol maximum ratio combining unit sends the scrambling code and channelization code information of each high-speed uplink data service user to the interference reconstruction unit;

3. The multi-user interference cancellation RAKE receiver apparatus according to claim 1, wherein said interference reconstruction unit comprises: a comparator, an accumulator, a pulse shaping filter, an interpolation filter, and a comparison A first multiplier, a second multiplier, a scrambling code, and a channelization code generating module corresponding to each user between the accumulator and the accumulator, wherein:

a comparator, configured to receive data symbols of a data channel of each user of the high-speed uplink data service, and determine, according to an actual spreading factor of each user, whether the user needs to perform interference reconstruction, when the frequency factor is less than or equal to the first threshold , the first multiplier corresponding to the user is sent, otherwise, 'the data symbol of the data channel of the user is directly output for symbol level processing;

a first multiplier, multiplying a data symbol of the data channel received from the comparator with a channel estimation parameter of the user, to obtain a data symbol with channel information, and sending the data symbol to the second multiplier; the scrambling code and the channelization code generating module Generating, according to the actual spreading factor, scrambling code and channelization code parameter of the user received from the control channel symbol processing unit, the scrambling code and the channelization code of the user are sent to the second multiplier;

An accumulator for accumulating chip data with channel information received by a second multiplier corresponding to each user of the high speed uplink data service, and obtaining chip data of the reconstructed channel information of all users is output to the pulse forming filter; a pulse shaping filter, which performs pulse shaping processing on the reconstructed chip data with channel information of all high-speed uplink data service users, and sends the chip data to the interpolation filter;

The interpolation filter interpolates the reconstructed chip data with channel information of all users after the pulse shaping process, and obtains interference data of the same sampling rate as the actual initial antenna data of the user, and outputs the interference data to the interference cancellation unit.

4. The multi-user interference cancellation RAKE receiver apparatus according to claim 1, wherein the interference reconstruction unit receives a data symbol of a data channel of a high speed uplink data service user from a data channel symbol maximum ratio combining unit, When it is judged according to the spreading factor therein whether the user needs to perform interference reconstruction, if the spreading factor is greater than the first threshold, the data symbols of the user's data channel are directly output for symbol level processing.

5. The multi-user interference cancellation RAKE receiver apparatus according to claim 1 or 3 or 4, wherein the first threshold of the spreading factor is equal to ^four .

6. The multi-user interference cancellation RAKE receiver apparatus according to claim 1, wherein the interference cancellation unit comprises a delayer and a subtractor, wherein:

a delay device, configured to delay initial antenna data input from the antenna end, and align the initial antenna data with interference data received from the interference reconstruction unit;

The subtracter is configured to perform subtraction on the commonly input delay-aligned initial antenna data and the interference data outputted by the interference reconstruction unit, and output antenna data that is cancelled by the high-speed uplink data service signal, and send the antenna data to the delay control The unit is used for data demodulation of other non-high speed uplink data service users.

7. A method of operating a multi-user interference cancellation RAKE receiver apparatus according to claim 1, comprising the steps of:

(2) The high-speed on the input spreading factor is less than or equal to the first threshold by the interference reconstruction unit The data symbols of the data service user data channel are subjected to interference reconstruction, and interference data having the same sampling rate as the initial antenna data is obtained and sent to the interference cancellation unit;

(3) The initial antenna data received by the interference cancellation unit after delay control is aligned with the interference data outputted from the interference reconstruction unit, and subtracted, and the antenna data with the interference removed is sent to the antenna data delay control unit, and extended. The time control is used for RAKE demodulation of other users.

8. The working method according to claim 7, wherein the step (1) further comprises:

(1 - 4) demodulating the RAKE demodulation unit into a data channel of each user subsequently sent by the data channel symbol maximum ratio combining unit according to the channel estimation value sent by the control channel symbol processing unit and the actual spreading factor The data symbols are subjected to channel compensation and maximum ratio combining, and the data symbols of the data channel of the high-speed uplink data service user are sent to the interference reconstruction unit.

The working method according to claim 7, wherein the step (2) further comprises:

Receiving, by the comparator, the data symbols of the data channel of each user, comparing the actual spreading factor and the first threshold, and directly outputting the data symbols of the data channel of the user when the spreading factor is greater than the first threshold, otherwise Multiplying the data symbols of the received data channel with the channel estimation parameters of the user by using the first multiplier corresponding to the user to obtain channel information. a data symbol, wherein the value of the first threshold is 4;

Generating the scrambling code and the squaring code of the user by the scrambling code and the channelization code generating module according to the actual spreading factor, scrambling code and channelization code parameter of the user received from the control channel symbol processing unit;

Encrypting and scrambling the data symbols with channel information received from the first multiplier by the second multiplier according to the scrambling code and the channelization code of the user received from the scrambling code and the channelization code generating module a multiplication operation, outputting the chip data of the user with channel information to the accumulator;

And accumulating chip data with channel information received from a second multiplier corresponding to each user by an accumulator, and obtaining chip data of the reconstructed channel information of all users is output to a pulse shaping filter;

10. The working method according to claim 7, wherein the step (3) is further divided into:

The antenna data of the common input delay alignment and the antenna interference data output by the interference reconstruction unit are subtracted by the reducer, and the antenna data with the high-speed uplink data service signal interference is outputted, and sent to the antenna data delay control unit. After delay control, it is used for RAKE demodulation of other non-high speed uplink data service users.